Sheetweb Spider – Drapetisca alteranda

Exquisitely camouflaged, this spider is suspended on her sheet web.

Linyphiidae is the second largest family of spiders after Salticidae.  Comprised of 4,300 described species in 578 genera, this family is poorly known because of their small size.  Commonly called sheetweb spiders (subfamily Linyphiinae) and dwarf spiders (subfamily Erigoninae).

Sheetweb spiderwebs can be flat, convex or concave, or can simply hug the substrate contours, as this spider demonstrates. She has constructed her web on a fallen log, drenched in condensation on the forest floor – an environment not particularly conducive to the rapid movement she needs to capture prey. So instead of mucking about in the moss and lichens and liquid, this spider is supported on silken strands she grips with claws at the tips of her legs. This gives her the advantage of speed, and also imparts a network whereby prey movements are communicated almost instantly to her vibration-sensing equipment.

I see orb-weavers remain hidden while surreptitiously holding a thread integrated into the orb; it works just like a child's tin-cans-and-string telephone. (Tin-can telephones really do work, in case you've never tried it, soup manufacturers' TV ads notwithstanding; the key being the string must be stretched taut in a straight line between the cans, thereby very effectively transmitting the sound of a human voice through the serial connection of fiber.)